The elements of m are read using this index order. ‘C’ means to
index the elements in C-like order, with the last axis index
changing fastest, back to the first axis index changing slowest.
‘F’ means to index the elements in Fortran-like index order, with
the first index changing fastest, and the last index changing
slowest. Note that the ‘C’ and ‘F’ options take no account of the
memory layout of the underlying array, and only refer to the order
of axis indexing. ‘A’ means to read the elements in Fortran-like
index order if m is Fortran contiguous in memory, C-like order
otherwise. ‘K’ means to read the elements in the order they occur
in memory, except for reversing the data when strides are negative.
By default, ‘C’ index order is used.

Returns:

ret : matrix

Return the matrix flattened to shape (1, N) where N
is the number of elements in the original matrix.
A copy is made only if necessary.